Ongoing Hurricane Sandy repair work on the R-train tunnel has dumped thousands of riders onto other Brooklyn lines, creating cattle-car conditions that are too much even for a former NFL player to handle.

“Here’s the worst part: the pushing,” said Devale Ellis, who played wide receiver for the Detroit Lions.

“The people getting onto the train start pushing because everyone’s not sure when the next train’s going to come,” Ellis, 29, added.

The R train’s damaged Montague tube was shut down in August, sending displaced straphangers to alternate subway lines. Since then, C-train ridership has jumped 40 percent during morning peak periods, according to new MTA data obtained by the Riders Alliance and Straphangers Campaign.

“I feel like a sardine packed in a can,” Ellis told The Post. “It’s the worst feeling in a world.”

The MTA said there were an additional 32 riders per car at the Jay Street-MetroTech station between 8:30 and 9:30 a.m. from September to November of last year, as compared with the months of January to June.

The extra passengers bring the C train to a near- capacity level of 98 percent, up from 70 percent.

“That’s inhumane,” said Kahtrell Lewis, a 23-year-old member of the Riders Alliance, blasting the overcrowding. “You can’t move. Everyone is on top of each other.”

He added that passengers at the Hoyt-Schermerhorn station often have to watch two or three trains go by before they can squeeze in.

The C isn’t the only line where riders are squeezed. The A train saw a 21 percent increase between 8 a.m. and 9 a.m. at Jay Street-MetroTech station.

And at the nearby Borough Hall station, ridership on the 4 line is up nearly 24 percent from 59 to 73 travelers car, while the 5 train saw a 22 percent increase.

“People are pushing and yelling to get onto the train,” said John Raskin, the Riders Alliance executive director. “It’s really intolerable in the morning rush.”

The Riders Alliance will launch a campaign in February to improve service on the C line.

Even before Sandy, the C was a troubled line — ranked the worst four years in a row by the Straphangers Campaign for its dirtiness, hard-to-hear announcements and car breakdowns.

An MTA spokesman said all of the subway lines are operating under capacity and that the authority planned for them to absorb R-train riders during Sandy repairs.

The Montague tube, which connects Downtown Brooklyn with lower Manhattan, was devastated during Hurricane Sandy in October 2012, when it was flooded with 27 million gallons of saltwater. It was closed over the summer for repairs.

The R train currently runs in two sections — one from Bay Ridge to Downtown Brooklyn, and another from lower Manhattan to Forest Hill in Queens.